I am using this antenna:
http://www.sdarsantennas.com/prod_552.aspx
centered above the hatch, running the cable under the weatherstripping and then under the headliner trim to the passenger side door trim where it comes down and connects to the receiver under the seat. The whole install took about 25 minutes. I used a dull butterknife to push the wire under the trim. The antenna is has a very low profile and is hardly noticeable.